36 
Plate Y 
Figures 1-3. Helisonia trirolvis macroxtomum (Whiten ves) . Lectotype from Mile-end Toll 
Gate, Montreal, Canada. Specimens from Perth Municipal Museum, now in National 
Museum of Canada, No. 3809 (lectotype, lower figure); 3870 (paratypes, upper 
figures) . 
Figures enlarged 2 diameters. 
